The present invention relates to an auxiliary element for the segmented distalisation of the posterior jawbone sector from canine to molar in orthodontic treatment which is to improve, both mechanically and aesthetically, the elements which, with this same function, are currently being used.
The use of auxiliary elements in orthodontic treatment to achieve segmented distalisation by the inverse anchorage method is already known in current practice from the book “El Anclaje Inverso y su Ecuacin” (“Inverse Anchorage and its Equation”), which envisages leaving the premolars free by means of a modular section.
In current practice the modular section is a segment of rectangular wire which is anchored on an independent element cemented on the molar in the form of a small ring, called a strip, by the distal or posterior part, while the mesial or anterior part is anchored to a bracket cemented directly on the surface of the canine.
Said modular section is metallic and is constructed by the orthodontist in the clinic, being removable without having to move the posterior or distal strip or the anterior or mesial bracket.
The function of said modular section is to force the distalisation of the posterior sector of the molar to the canine by using elastic intermaxillary bones.
Given its characteristics of structural rigidity, it also necessitates, in an active manner, rotation of the upper molar on its palatial root.
The auxiliary element for the segmented distalisation of the posterior jawbone sector from canine to molar in orthodontic treatment which forms the basis of the present invention is formed by two parts, and anterior or mesial segment which has a blunt projection upwards and forwards, with a retaining function for the use of elastic strips cemented on the vestibular surface of the upper canine being adapted to the curved anatomy of this facet and running up to its distal part in an arched shoulder, but without contacting the vestibular facets of the premolars, until it reaches the vestibular facet of the molar of the same side, finishing in an articulated ball-and-socket member.
The second segment is that which is cemented on the vestibular facet of the upper molar and consists of a base with blunt curves with a receptacle in its middle and outer parts, intended to house the ball-and-socket member which constitutes the distal element of the mesial segment.
The multi-direction articular movement, although limited because of the distalisation and rotation of the upper molar on the palatal root, os produced by the effect of the intermaxillary elastic elements.
Fitting and assembly of the two parts of the sectional apparatus for the distalisation is done before cementing in the patient's mouth.
The fundamental advantage of the apparatus of the present invention, with respect to that currently known, lies in the design and in the type of production of the segmented distalisation in which the molar, already known in practice, is forced to rotate by means of the rotation of the activated rectangular arc and is anchored on its vestibular surface, in contrast to the sectional distalisation element, which constitutes the basis of the present invention in which rotation is produced by the exclusive action derived from the use of the elastic intermaxillary elements of class II.
On the other hand, the configuration of the element facilitates its manufacture with materials which can include translucent or transparent materials which give it aesthetics totally distinctive to those elements currently used and represents an important psychological aid for people who use it.
A variation of the present invention relates to the type of interrelation between the end of the mesial segment and the distal segment, whose interrelation is achieved by means of a spherical ball-and-socket member and transverse cylindrical articulation bolt which can be fixed in the body of the distal segment, adjusting to an orifice of the ball-and-socket member and allowing rotation thereof, said interconnection being achieved, in another variation, by means of a transverse cylindrical bolt arranged in an orifice of polygonal shape, for example square, of the spherical ball-and-socket member part associated with the distal end of the mesial segment.
Said variation relates to a new embodiment of the expansion for fastening of the elastic element, which adopts a slim and relatively long structure with a curvature adapted to that of the retaining base of the mesial segment.
To facilitate explanation, a few pages of drawings accompany the present description, in which by way of illustrative but non-limiting example is shown one embodiment of an auxiliary element for the segmented distalisation of the posterior jawbone sector from canine to molar in orthodontic treatment according to the principles of the present invention.